Measuring and Reporting Fly Ash Resistivity

Compliance with the 1970 Clean Air Act has required a major improvement in electrostatic precipitator performance to meet the more stringent particulate removal requirements. This has introduced a number of new design problems as well as difficulties in evaluating coal and ash quality in terms of required precipitator collection surface. The influence of fly ash chemistry on ash resistivity has become a problem of major concern and has emphasized the need for standard criteria for uniform reporting and measurement of ash resistivity. This paper reviews a number of these problems as a Phase 1 effort. Its intent is to provide the essential technical background leading to the future preparation (Phase II) of a Standard for reporting resistivity, including some updating of laboratory resistivity measurement techniques.